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J Marti

Publications and source records attributed to J Marti.

At least 19 recordsLinked to original sources
PubMed2006

Molecular simulation of liquid water confined inside graphite channels: thermodynamics and structural properties.

We carried out molecular dynamics simulations to describe the properties of water inside a narrow graphite channel. Two stable phases were found: a low-density one made of water clusters adsorbed on the graphite sheets and a liquid one that fills the entire channel, forming several layers around a bulk-like region. We analyzed the interfacial structure, orientational order, water residence times in several regions, and hydrogen bonding of this last water phase, calculating also a quantity of electrochemical interest, the probability of electron tunneling through interfacial water. The results are in good qualitative agreement with the available experimental data.

Journal Article↗
PubMed2005

Cost/efficacy clinical trial about the use of T-tube in cadaveric donor liver transplant: preliminary results.

UNLABELLED: Biliary reconstruction is the most common cause of morbidity associated with orthotopic liver transplantation. Our objective was to assess the complications and hospital resources related to the use of a T-tube. MATERIAL AND METHODS: Among 95 liver transplants performed from October 2002 to November 2003, 84 patients were randomized to receive a T-tube or no T-tube. We analyzed all patients with a follow-up of at least of 3 months. RESULTS: Fifty-five transplants were analyzed with 8 months mean follow-up, including twenty eight with T-tube and twenty seven without a T-tube. No patient died during the follow-up. The overall rate of biliary complications was 45.4% (25/55) including 21/28 (75%) in the T-tube group and 4/27(14.8%) in the non-T-tube group (P < .0001). Complications related to T-tube extraction occurred in 48.2% (13/27), including 3 cholangitis and 10 leaks. The costs of hospital resources due to radiological studies were 5329 capital JE, Ukrainian for the T-tube group vs 5785 capital JE, Ukrainian for the non-T-tube group. The costs of hospital resources due to treatment were 28,280 capital JE, Ukrainian for the T-tube group vs 10,088 capital JE, Ukrainian for the non-T-tube group. CONCLUSIONS: Use of a T-tube during orthotopic liver transplantation does not seem justified. Biliary anastomosis stenting is followed by an increased incidence of complications, most of which are related to its use. Hospital stay, radiological studies, and cost of hospital resources are higher among the T-tube patients. Therefore its systematic use is not advisable.

Anastomosis, Surgical↗
PubMed2004

Characterization of human FCGR3B*02 (HNA-1b, NA2) cDNAs and IMGT standardized description of FCGR3B alleles.

The low-affinity Fc gamma receptor IIIb (Fc gamma RIIIb and CD16b) is constituted by a unique FCGR3B polypeptide chain that comprises two extracellular immunoglobulin-like domains, and is expressed as a glycosylphosphatidyl inositol-anchored receptor on the neutrophils. The FCGR3B chain bears allotypes that define the human neutrophil antigen-1 (HNA-1 and NA) system involved in major post-transfusional reactions. FCGR3B is highly homologous to FCGR3A, which is expressed as a transmembrane receptor on natural killer cells and monocytes/macrophages. Its transcription products were not yet fully characterized. In the present work, we sequenced FCGR3B cDNAs with complete 3' untranslated region from purified granulocytes of HNA-1b/HNA-1b (NA2/NA2) genotyped donors. We characterized two FCGR3B cDNAs of different lengths corresponding to two polyadenylation sites. This result was corroborated by data raised by serial analysis of gene expression (SAGE). FCGR3B allele polymorphisms, from this article [FCGR3B*02 (HNA-1b, NA2)] and from the literature, are described for the first time according to the IMGT standardized nomenclature and to the IMGT unique numbering for C-LIKE-DOMAIN (http://imgt.cines.fr). These rules, described in the IMGT Scientific chart, are based on the IMGT-ONTOLOGY concepts. IMGT allele alignments and IMGT Collier de Perles graphical two-dimensional representations are provided for the two Ig-like domains (or C-LIKE-DOMAINs) [D1] and [D2] of FCGR3B*02. The standardized description of FCGR3B allele polymorphisms was approved by the IMGT Nomenclature Committee (IMGT-NC) and is freely available in IMGT repertoire at IMGT, http://imgt.cines.fr.

Alleles↗
PubMed2003

Analysis of adiabatic coupling between photonic crystal single-line-defect and coupled-resonator optical waveguides.

A detailed analysis of adiabatic coupling between conventional photonic crystal single-line-defect and coupled-resonator optical waveguides is reported. Adiabatic coupling by progressive variation of the radii of the spacing defects between cavities is investigated. Flat transmission spectra with coupling efficiencies greater than 90% are achieved in a broad frequency range with short coupling lengths. Moreover, we find that flat transmission at low frequencies requires longer coupling lengths partly because the requirements imposed for adiabatic transmission in photonic crystals are violated.

Journal Article↗
PubMed2002

Haloperidol dose for the acute phase of schizophrenia.

BACKGROUND: Haloperidol is a benchmark, accessible antipsychotic against which the effects of newer treatments are gauged. OBJECTIVES: The primary goal of this review is to determine the best range of doses for haloperidol for the treatment of people acutely ill with schizophrenia. SEARCH STRATEGY: The reviewers searched Biological Abstracts (1980-1999), CINAHL (1982-1999), The Cochrane Library (1999, Issue 2), The Cochrane Schizophrenia Group's Register (December 1999), EMBASE (1980-1999), MEDLINE (1966-1999) and PsycLIT (1887-1999). They also inspected all references of all identified trials and included studies sought as a citation on SCISEARCH database (1980-1999). Authors of identified studies and pharmaceutical companies were also contacted. SELECTION CRITERIA: Studies were selected if they involved people being treated for acute schizophrenia, randomised to two or more dose ranges of non-depot haloperidol, and if they reported clinically meaningful outcomes. DATA COLLECTION AND ANALYSIS: The reviewers independently and blindly inspected citations (10% reliability check), they ordered papers, and reliably re-inspected and quality assessed the full reports. The reviewers, again working independently, also extracted data. For homogeneous dichotomous data the relative risk (RR), 95% confidence intervals (CI) were calculated on an intention-to-treat basis. Reviewers assumed that people who left the study early or were lost to follow-up had a negative outcome. Weighted mean differences (WMD) were calculated for continuous outcomes that reported intention to treat (ITT), last observation carried forward (LOCF) data. Data was excluded if loss to follow-up was greater than 50%. MAIN RESULTS: Sixteen trials with nineteen different randomised dose comparisons were included. No studies reported data on relapse rates, quality of life and none compared >1.5-3.0 mg/day haloperidol to higher dose ranges. Using low doses (>3-7.5mg/day) did not clearly result in loss of efficacy (no clinically important improvement in global state, versus >7.5-15mg/day n=48, 1 RCT, RR 1.09 CI 0.7 to 1.8; versus >15-35mg/day n=81, 2 RCTs, 0.95 CI 0.8 to 1.2). Doses of haloperidol in the range of >3-7.5 mg/day had a lower rate of development of clinically significant extrapyramidal adverse effects than higher doses (clinically significant extrapyramidal adverse effects, versus >7.5-15mg/day n=64, 2 RCTs, RR 0.12 CI 0.01 to 2.1; versus >15-35mg/day n=144, 3 RCTs RR 0.59 CI 0.5 to 0.8, NNH 3 CI 2 to 6; versus >35mg/day n=86, 2 RCTs, RR 0.70 CI 0.5 to 1.1). All other comparisons between dose ranges did not yield statistically significant differences, but several, particularly with lower dose ranges, were underpowered to detect clinically meaningful differences. REVIEWER'S CONCLUSIONS: No results are conclusive and all are based on small, short, studies. It would be understandable, however, if clinicians were cautious in prescribing doses in excess of 7.5 mg/day of haloperidol to a person with uncomplicated acute schizophrenia, and if people with schizophrenia were equally reticent to take greater doses. Further research is needed regarding the efficacy and tolerability of the >1.5-3.0 mg/day dose range.

Acute Disease↗
PubMed2001

Cigarette smoking behavior among US Latino men and women from different countries of origin.

OBJECTIVES: This study sought to compare smoking behavior among Latino men and women from different countries of origin. METHODS: A telephone-administered survey was conducted in 8 cities with Latino men and women of different national origin living in census tracts with at least 70% Latino individuals. RESULTS: A total of 8882 participants completed the survey; 53% were women. The average age of respondents was 44 years; 63% were foreign-born, and 59% preferred Spanish for the interview. Current smoking was more prevalent among men (25.0%, 95% confidence interval [CI] = 23.7, 26.3) than among women (12.1%, 95% CI = 11.1, 13.0). Smoking rates were not significantly different by national origin among men, but Puerto Rican women had higher rates of smoking than other women. Central American men and women had the lowest smoking rates. Foreign-born respondents were less likely to be smokers (odds ratio [OR] = 0.77, 95% CI = 0.66, 0.90) than US-born respondents, and respondents with 12 years or less of education had an increased odds of smoking (OR = 1.17, 95% CI = 1.01, 1.35). High ac culturation was associated with more smoking in women (OR = 1.12, 95% CI = 1.00-1.25) and less smoking in men (OR = 0.86, 95% CI = 0.78-0.95). Puerto Rican and Cuban respondents were more likely to be current smokers and to smoke more than 20 cigarettes per day. CONCLUSIONS: Older, US-born, and more-educated respondents were less likely to be current smokers. Respondents of Puerto Rican and Cuban origin were more likely to smoke. Acculturation has divergent effects on smoking behavior by sex.

Acculturation↗
PubMed2000

Discovery of a high-energy gamma-ray-emitting persistent microquasar

Microquasars are stellar x-ray binaries that behave as a scaled-down version of extragalactic quasars. The star LS 5039 is a new microquasar system with apparent persistent ejection of relativistic plasma at a 3-kiloparsec distance from the sun. It may also be associated with a gamma-ray source discovered by the Energetic Gamma Ray Experiment Telescope (EGRET) on board the COMPTON-Gamma Ray Observatory satellite. Before the discovery of LS 5039, merely a handful of microquasars had been identified in the Galaxy, and none of them was detected in high-energy gamma-rays.

Journal Article↗
PubMed2000

Social networks and cancer screening in four U.S. Hispanic groups.

BACKGROUND: Evidence shows that social relationships play an important role in health and health behavior. We examined the relationship between social networks and cancer screening among four U.S. Hispanic groups. METHODS: We used telephone surveys to collect data in eight U.S. regions that have concentrations of diverse Hispanic-origin populations. We interviewed 8903 Hispanic adults, for a response rate of 83%; analysis was restricted to the 2383 women aged > or =40. As a measure of social integration, we formed a social network index from items on the number of close relatives and friends, frequency of contact, and church membership. We used logistic regression to estimate the effects of social integration on screening, adjusting for sociodemographic factors. RESULTS: Among Mexican, Cuban, and Central-American women, the effect of social integration on mammography screening was slight. The odds ratios (OR) per unit change in social integration category ranged from 1.16 to 1.22 with confidence intervals (CI) that overlapped with the null. For Pap smear screening, the effect was strongest among Mexican-American women (OR=1.44, 95% CI=1.21 to 1.72), but also evident among Central-American women (OR=1.22, 95% CI=0.72 to 2.06) and Cuban women (OR = 1.25, 95% CI = 0.81 to 1.93). Among Puerto Rican women, social integration had no effect on either mammography (OR=1.03) or Pap smear screening (OR=1.08). CONCLUSIONS: Independent of socioeconomic factors, social integration appears to influence cancer screening participation of Hispanic women. The modest effect is not universal across Hispanic groups and was stronger for Pap smear than for mammography screening behavior. Researchers should recognize Hispanic group differences in social network characteristics and the potential of social networks to change screening behavior.

Adult↗
PubMed2000

Breast cancer screening in regional Hispanic populations.

Although Hispanics' use of breast cancer screening services has been investigated, to date there have been no published studies of distinct Hispanic populations in different areas of the country. Using the diverse populations and sites involved in the National Hispanic Leadership Initiative on Cancer 'En Acción', this study examines ethno-regional differences in breast cancer screening rates among these groups and explores the correlates of screening participation. Data collected through telephone surveys were analyzed for women 40 years of age and older (n = 2082). After controlling for demographic variables traditionally related to breast cancer screening rates, it was found that ethno-regional differences in breast cancer screening practices clearly persisted. In addition to traditional demographic factors, other variables evidently underlie differences in Hispanics' utilization of breast cancer screening services. These variables may be cultural and should be investigated in future research. Meanwhile, researchers should not refer to the 'Hispanic' population at large without identifying, addressing and clarifying the ethno-regional characteristics of their samples.

Adult↗
PubMed2000

Dynamic properties of hydrogen-bonded networks in supercritical water

Dynamic properties of supercritical water at temperatures between 573 and 773 K and densities between 0.49 and 0.83 g/cm(3) have been investigated by molecular dynamics simulation and compared to states located on the vapor-liquid coexistence curve. A flexible simple point charge potential has been assumed for interactions in the subcritical states, whereas a reparameterization of that model has been performed to model the supercritical states. The hydrogen bonding structure and the diffusion coefficients in an ensemble of simulated states were previously analyzed and a good agreement with available experimental data was found. Dynamic properties of hydrogen bonding like the bond lifetimes and the influence of hydrogen bonds in the vibrational spectra are discussed along a range of simulation conditions. A nonlinear behavior of the hydrogen-bond lifetime as a function of temperature is observed in subcritical water whereas a linear dependence is found in supercritical water. Special attention is paid to the intermolecular vibrational spectrum (10-400 cm(-1)). It has been observed that the mode centered at 200 cm(-1), attributed to the intermolecular O-O stretching vibration in the ambient state remains active in the supercritical states.

Journal Article↗
PubMed1999

Differential expression of the RTP/Drg1/Ndr1 gene product in proliferating and growth arrested cells.

Using a differential display method to identify differentiation-related genes in human myelomonocytic U937 cells, we cloned the cDNA of a gene identical to Drg1 and homologous to other recently discovered genes, respectively human RTP and Cap43 and mouse Ndr1 and TDD5 genes. Their open reading frames encode proteins highly conserved between mouse and man but which do not share homology with other know proteins. Conditions in which mRNAs are up-regulated suggest a role for the protein in cell growth arrest and terminal differentiation. We raised antibodies against a synthetic peptide reproducing a characteristic sequence of the putative polypeptide chain. These antibodies revealed a protein with the expected 43 kDa molecular mass, up-regulated by phorbol ester, retinoids and 1,25-(OH)2 vitamin D3 in U937 cells. It was increased in mammary carcinoma MCF-7 cells treated by retinoids and by the anti-estrogen ICI 182,780 but not by 4-hydroxytamoxifen. The mouse Drg1 homologous protein was up-regulated by retinoic acid in C2 myogenic cells. The diversity of situations in which expression of RTP/Drg1/Ndr1 has now been observed shows that it is widely distributed and up-regulated by various agents. Here we show that ligands of nuclear transcription factors involved in cell differentiation are among the inducers of this novel protein.

Amino Acid Sequence↗
PubMed1999

Transforming growth factor-beta1 is an autocrine mediator of U937 cell growth arrest and differentiation induced by vitamin D3 and retinoids.

Vitamin D and retinoids cooperate to inhibit the proliferation and induce the differentiation of human myelomonocytic U937 leukemia cells. In the present work, we investigated the role of TGF-beta as an endogenous mediator of this process. We found that the TGF-beta1 precursor began to accumulate in cell culture supernatants soon after the addition of 1alpha,25 dihydroxyvitamin D3 (VD) and retinoids. We used neutralizing antibodies (AbTGF-beta) and antisense oligonucleotide (AS Oligo) to inhibit its possible effects. Our data demonstrated that AbTGF-beta partially inhibit the expression of the differentiated phenotype, as assessed by measurement of phagocytic activity, response to the chemotactic peptide fMLP, and lysozyme secretion. AS Oligo was also inhibitory, and the effects of AS Oligo and AbTGF-beta were cumulative. Cell growth inhibition induced by VD and retinoids was completely reversed, and differentiation was reduced by about 75% when both inhibitors were associated. Time course experiments based on the delayed addition of AbTGF-beta and AS Oligo showed that TGF-beta1 was required for cell differentiation 24 h after the addition of inducers. Studies on TGF-beta receptors revealed that, while the expression of type II receptor was stable, the level of type I TGF-beta receptor mRNA and the expression of the protein began to decline early during the differentiation process. As a whole, these results support the notion that an autocrine TGF-beta pathway, activated by VD and retinoids in U937 cells, is involved in the early steps of the process leading to cell growth arrest and differentiation.

Antibodies↗
PubMed1999

Hypospadias in a polar bear (Ursus maritimus).

Corrective surgery on a 1.5-yr-old male polar bear (Ursus maritimus) with hypospadias included amputation of the vestigial penis, bilateral orchiectomy with scrotal ablation, and distal perineal urethrostomy. Hypospadias in other species is a congenital deformity that may be caused by extra- and intrauterine factors resulting in a disruption of the testosterone balance during urethral development, but the causative mechanism in this bear is unknown. The urethrostomy site was functional without complications 8 mo after surgery.

Animals↗
PubMed1999

[Evaluation of arrhythmic risk in coronary insufficiency].

Half of all deaths occurring in patients with heart failure are sudden deaths probably related to a malignant ventricular arrhythmia. The pathophysiological mechanisms of these arrhythmias are unclear, but left ventricular function, hypokalaemia accentuated by diuretics and treatments altering inotropism play a definite role. Because of the diversity of aetiologies generating heart failure, the multiplicity of fatal arrhythmias and the multifactorial origin of these arrhythmias, there is no formal marker for the risk of sudden death in patients with heart failure, at the present time. In addition to the NYHA classification and detection of episodes of syncope, assessment of these patients must be as complete as possible, at least including repeated evaluation of the ejection fraction, Holter ECG monitoring and detection of delayed ventricular potentials.

Arrhythmias, Cardiac↗
PubMed1998

Carbon structures with three-dimensional periodicity at optical wavelengths

Porous carbons that are three-dimensionally periodic on the scale of optical wavelengths were made by a synthesis route resembling the geological formation of natural opal. Porous silica opal crystals were sintered to form an intersphere interface through which the silica was removed after infiltration with carbon or a carbon precursor. The resulting porous carbons had different structures depending on synthesis conditions. Both diamond and glassy carbon inverse opals resulted from volume filling. Graphite inverse opals, comprising 40-angstrom-thick layers of graphite sheets tiled on spherical surfaces, were produced by surface templating. The carbon inverse opals provide examples of both dielectric and metallic optical photonic crystals. They strongly diffract light and may provide a route toward photonic band-gap materials.

Journal Article↗
PubMed1997

Biological monitoring of styrene exposure and possible interference of acetone co-exposure.

The object of this study is the evaluation of some of the toxicokinetic effects of exposure to low concentrations of styrene, and the possible influence of simultaneous exposure to acetone. To this end we studied 19 workmen simultaneously exposed to both solvents. During a week of 4-h work shifts, the workmen underwent daily personal environmental monitoring and the collection of urine samples, at both the beginning and the end of the work period, for the determination of mandelic acid (MA) and phenylglyoxylic acid (PGA). The presence of the solvents in the atmosphere was evaluated using passive personal monitoring and gas chromatography. Average exposure to styrene and acetone were respectively 72.2 mg/m3 and 225.7 mg/m3. MA and PGA were quantified by high-performance liquid chromatography (HPLC). The daily urinary concentration averages, both at commencement and at the end of work shifts, of both the metabolites studied and of the sum of the two were in statistically significant linear correlation with the average daily styrene exposure. Concentrations of MA and PGA in urine samples collected at the start of the work shift averaged 61.5 mg/g creatinine and 45.2 mg/g creatinine respectively, representing 41% and 72% of those at the endo of the work shift which were 148.3 and 62.6 mg/g creatinine, respectively. With equal exposure to styrene, the average urinary concentrations of MA and PGA at both the beginning and end of the work shift increased significantly (P < 0.001) during the working week. Moreover, we found that with equal exposure to styrene, urinary excretion of MA, PGA and MA + PGA at the end of the shift was inversely correlated with the intensity of acetone exposure (r = 0.4659, 0.3410 and 0.542 respectively, P < 0.001). In conclusion, these results express slower urinary kinetics of styrene metabolites than is usually described in the literature, and favor a tendency to accumulate MA and PGA in the organism as a consequence of the retardation of urinary excretion kinetics. Acetone apparently represents one of the determining factors in this interference.

Acetone↗